1. Field of the Invention
This invention relates to a novel apparatus which is capable of treating body cavity fluids very efficiently and safely by the batch-wise concentration of body cavity fluids followed by filtration. The term "body cavity fluids" as used herein includes protein-containing fluids accumulated and retained in body cavities, such as ascitic fluid and pleural fluid.
2. Description of the Prior Art
There are a considerable number of patients who are suffering from hydrops of body cavities, such as ascites and hydrothorax, resulting from cirrhosis, renal failure or cancer of the viscera, among others. Recently, an apparatus for filtering and concentrating ascitic fluid for returning the concentrate intravenously to the patient has been proposed (see, for example, Japanese Patent Publication No. 80-15221). In such apparatus, ascitic fluid withdrawn from the abdominal cavity of an ascitic patient is filtered through a hollow fiber filter whereby cancer cells or bacteria are removed. The filtrate ascitic fluid is then concentrated by means of a hollow fiber concentrator to increase the concentration of useful proteins, and the resulting concentrated ascitic fluid is returned intravenously to the patient. This type of apparatus was developed to provide a safer system capable of overcoming the deficiencies of the prior art ascitic fluid-concentrating apparatus wherein, when unnecessary material such as bacteria and giant cells were present in the ascitic fluid, these too were also concentrated and returned to the patient.
However, there are further disadvantages associated with the above-mentioned ascitic fluid filtering and concentrating apparatus in that complicated control mechanisms are required for associated control of filtration and concentration and for control of the rate of concentration; and still further, two or more pumps are required so that the apparatus is complicated, troublesome to operate, large-sized and expensive.